Hi, welcome back to an introduction to breast cancer. I'm Dr. Anees Chagpar. I'm so glad you chose to join us today. Today, we're going to be talking about screening. How do we detect breast cancers early, so they are at the stage where they are most treatable? We talked a little bit about screening and we talked about high risk and how we can risk reduce by screening more frequently. Essentially, there are a few main modalities. The first is breast exam, whether this is done by yourself or by your clinician. The second is mammography. Third, ultrasound and fourth, MRI. We're going to talk a little bit about each of these modalities in turn. Let's start with a breast exam. Whether you do a breast exam yourself or whether your doctor does one for you, the elements are essentially the same. It starts with two positions. So I always examine people with their hands over their head and on their hips, squeezing tight, why? Because it gives you some idea of a different perspective of the breast. With your out stretched over your head sometimes you can see the skin dimpling in, which you wouldn't otherwise see. And sometimes when you squeeze your pectoral muscles, those are those chest press muscles, you get a sense of cancers that may be buried deeper in the breast. So it's important for your examination to examine people in both positions, sitting up, lying down, hands up over their head, hands on their hips. Let's get started. Remember that every exam starts with inspection. People often skip this step and go straight to feeling the breast tissue. But inspection gives us a lot of key information. For example, we want to see whether the two breasts are symmetrical, do they look the same? Is one bigger or smaller than the other? Is one red and not red? This gives us information. Always be suspicious of one breast that may be bigger or smaller than the other because it may reflect underlying pathology. Other things, look for dimpling or puckering, and this also may change in those two different positions. Sometimes it gives you a clue that there may be cancers pulling or tugging in on that skin. You want to look for a lump, which may be something you can see even before you feel it and always look at the nipple. Remember back when we talked about the breast. We said that the breast is made up of ducts and lobules. Most breast cancers come from the ducts, and those ducts all go to the nipple. So looking at the nipple is really important. You want to see if whether it's flattened or sometimes inverted. Sometimes people have had an inverted nipple for years and years, maybe even been something that they were born with. But if there's new nipple inversion, it's something to pay attention to. You want to look for any scaling of the nipple. When we talk later on about special forms of breast cancer like Paget's disease, that's going to be something that we pay attention to. And you're going to want to look for nipple discharge. Pay close attention to what kind of discharge it is. Is it clear or green, or is it blood looking red or dark? Is it coming from one breast or both? Is it something that comes spontaneous or is it something that you have to manually extricate. These give you a clue as to whether the nipple discharges what we call physiologic, which is essentially normal or pathologic, something you should be concerned about. Bloody unilateral, so one-sided only, spontaneous nipple discharge often reflects underlying pathology, and so you want to play close attention to that. After you've suspected the breasts both in two positions, you then want to go on to palpation, feeling the breasts and the lymph nodes. For this, it's important to note where the lymph nodes are where breast cancers can drain. This essentially are the cervical, supraclavicular, infraclavicular and axillary lymph nodes. So these are the lymph nodes underneath your jaw, underneath your chin on both sides of this muscle called the sternocleidomastoid muscle. The anterior cervical chain, the posterior cervical chain as well as the super clavicular, those lymph nodes on top of your collar bone and infer clavicular, those below your clavicle. Many breast cancers can spread to these cervical lymph nodes. But by far, the most common basin, the most common place where breast can spread is underneath your armpit, in the axillary lymph nodes. When we talk about staging later on and ultimately when we talk about treatment, we're going to pay particular attention to those axillary lymph nodes. So on your physical exam, it's important that you feel for those lymph nodes, and see if you can feel any that are swollen or hard particularly if they're not movable, then you want to examine the breast. Now, it's important when you do a breast examine that you remember the anatomic boundaries of the breast. The breast goes all the way up to the collar bone, all the way over to the breast bone in the midline. All the way down to the sixth rib or the inframammary fold and down into your arm pit. So when you examine the breast, it's really important that you examine the whole breast so that you get an idea of what's going on in all of the breast tissue. Many people talk about different techniques of doing a breast exam. Some people go around and around in a circular fashion. Other people use a wedge type fashion, where they go from the nipple and extend out towards the periphery of the breast. Other people use what's called a lawnmower or a vertical sweep, where they start at the clavicle and they go all the way down and then back up to the top. It doesn't really matter which technique you use, so long as you examine the whole breast. So what are you feeling for? Essentially you're feeling for a lump. Now many women particularly if they're doing self breast exams, get very concerned with this. Because in general women have lumpy bumpy breast tissue and it causes some anxiety because how do you know whether a lump is a lump, or whether it's a bad lump? Well this is where getting to know your breasts is a good idea. So a lump that has changed or is different or wasn't there last month, maybe something that you're more concerned about. As clinicians you want to be paying particular attention to lumps that are firm, hard. It doesn't really matter whether they're mobile or not. Many breast cancers continue to be mobile. But you want to pay attention to all of those factors. How big is this? Is it symmetrical? Does it feel like it's got irregular borders? Can you move it? How big is it? All of these things are going to be factors, that you're going to record, both in your mind, and in your note. Well, beyond the breast exam, how else can we screen for breast cancers? By far the most common is mammography. Mammography is really revolutionized how we treat breast cancer. Because as opposed to clinical breast exam where a lump needs to be a reasonable size for us to detect it by physical exam, on mammography we can often find cancers before we can ever feel them. On a mammogram, we're looking for things like little calcium spots called calcifications, which can often reflect the first signs of cancer or precancer. We can also find masses or asymmetries between the two breasts. Now, there are many different kinds of mammograms. Some may be on a bus or a mammogram van that goes around the neighborhood. Other people may get a mammogram at a free standing facility. It doesn't really matter where you get your mammogram done. Mammograms also come in different forms. Historically, we used what's called analog, or film screen mammography. Nowadays, we use digital. It's very much analogous to a camera. Before we had film cameras. But I would hazard to say that these days oftentimes we use digital. Now, the picture that we take is essentially the same, but with a digital camera, we have the ability to tweak the pictures right on our computer screen. It's the same thing with mammography. So while digital and analog cameras can both give us the same pictures and digital and film screen mammography can give us the same pictures. With digital mammography we often can get better resolution on our computer screens, so we know that the call back rate, the chances of us needing to call back a patient so that we can get a better image, is reduced. Nowadays, we have another form of mammography as well. This is called 3D mammography, or tomosynthesis. Very much like taking slices through a loaf of bread, what tomosynthesis does is it takes pictures like a CT scan through the breast tissue. These thin slices then allow the mammographer, or the breast imager, to page through this thick tissue and get individual slices of images. Giving them a 3D reconstruction of the breast. Let's take a look at mammograms and learn how we can interpret what we see. Here's a standard four-picture view of a mammogram. Any time you have a mammogram, you'll always get four pictures, two from each side. One view is with the breast squished side to side. So you're looking from the side. This gives you a picture of the breast in an up down plane. The other picture is taken with the breast squished top to bottom, so it gives you a view looking down on the breast from a side to side plane. When you look at these pictures, one is labeled RMLO, that's the right breast with the medial lateral oblique compression. So the breast squished side to side, like this. Then you have the LMLO picture. The same thing on the left breast. RCC stands for the right cranial caudal compression view. So the breast is squished from the cranium, the head, to the caudal, the bottom. So squished in an up down plane, giving you information from a side to side projection, and then you have the LCC, or the left cranial caudal view. So how do you know how to hang these pictures? Which side's the top? Which side's the bottom? Which side's the inside, and which side's the outside? The little trick I always use is that the marker is always in the armpit. And if you remember that, you'll never go astray. So, when we look at this picture, one of the things that we can see is that there's a bright white spot, right there in the right breast. You can see it on this view right here. It's not in the left breast. So, where is that little spot? Well, using the convention that we just learned, we know that it's in the upper part of the breast. Because it's in the top half of the right MLO view. We also know that it's in the outer part because it's towards the marker on the right CC view. So this is an abnormal mammogram. There's a mass in that view. This is when patients are often called back for a diagnostic mammogram. A diagnostic mammogram, as opposed to a screening mammogram, is one where we take a closer look at some of the abnormalities that we may have seen in a screening mammogram. In this case, we would want a magnified view of that mass. And when we get that, we can see that this is a speculated mass. Speculated is a term that you'll often see on a mammogram. It means a stellate, starburst shape. You can see that this has got lots of little rays that emanate from the center, and lots of fine little white spots. Those are calcifications. It's important to remember that those calcifications have nothing to do with how much calcium you eat or drink. But they can be the first signs of cancer or pre-cancer. So this is a very concerning mammogram. Now, one question that often comes up is, do mammograms really save lives? No woman ever likes to have their breasts squished, but we do know from randomized controlled trials, that mammograms do make a difference. This is a meta analysis. A meta analysis is a study that puts together very good studies often randomize controlled trials to get at a composite effect. So an answer to the question of do mammograms actually work, putting together the data from many other studies. And what you can see here is that no matter which age range you look at, from 39 to 49, 50 to 59, 60 to 69, the relative risk, that is to say the risk of death when you have somebody who had a mammogram compared to somebody who did not have a mammogram is less than one. So, in general, there's about 15% risk reduction even for patients as young as 40 for dying when they get a mammogram. The best age range is right here, 60 to 69, where the risk reduction of mortality is almost 32%. Where we don't have sufficient data, is in patients who are older than age 70. You can see that there was only one trial that looked at women between the ages of 70 and 79, and truthfully found no difference. Between whether they had a mammogram and whether they didn't have a mammogram in terms of overall mortality. The number needed to prevent one cancer death is shown here. This tells you the absolute effect. So you need to treat or do mammograms on 1900 women between the ages of 39 and 49 to prevent one cancer death, but you can see that in older women, you only need to do mammograms in 377 patients to prevent one cancer death. So why is that? Why does age make a difference? Well, one reason is that breast cancer generally occurs more so in older patients. So there's a higher likelihood of finding cancer in older women. The second is that younger women have a longer life expectancy to begin with. So the chances of preventing death go down because they have longer to live. But a third reason has to do with breast density. What is breast density? We hear a lot about it in the news. In fact, there are many organizations that have taken up the rallying cry that women should know about breast density. And here's why. Density is how white is your mammogram. Mammograms, as you saw, are black and white images. Your breast is made up of fibrous tissue which on a mammogram looks white, and fatty tissue, which on a mammogram looks black. Well, cancers on a mammogram look white, and as you can imagine, it's harder to see a white cancer on a white background than it is on a black background. And so, the radiologists have classified mammographic density into four categories. There are breasts that are entirely fat, or almost entirely fat, like this picture on the left. It would be pretty easy to see a white cancer on that predominately black background. As you move from scattered fibroglandular densities to heterogeneously dense to extremely dense breast tissue, you get breast that on a mammogram look pretty darn white, like this right most picture. It would be very difficult to see a white cancer, hiding in that white background. And that's the reason why, for patients who have really dense breast tissue, using another screening modality may be helpful. This is where ultrasound can come in. Ultrasound is very helpful in dense breasts. And that's because dense breast tissue looks grey on an ultrasound. But cancers look dark. And so it's easier to pick up that differentiation. Most commonly, ultrasounds are used to distinguish masses from being either cystic or solid. Let's take a look. The picture on the left shows you a cyst. It's perfectly round it tends to be wider than it is tall. And when we look at the breast tissue on this ultrasound, I often say that it looks like layers of a layer cake. You have the skin layer, you have a layer of subterraneous fat, you then have layers of breast tissue, and then muscle at the back. You can see that this mass, this cyst, is obeying the layers of the layer cake. It's kind of sitting and obeying the natural laws of the breast. Let's compare that to a more sinister breast cancer, the picture on the right. Here, you can see that this mass is irregular and it is not perfectly black. It's more grayish. It has irregular margins, and it's taller than it is wide. Look at it in terms of the layers of that layer cake. See the layers? See how it's cutting through those layers of the layer cake? It isn't obeying the laws of that normal tissue, and remember back to when we talked about cancer. Cancer is proliferation of abnormal cells. Cells that are disobeying all of the rules similar to this ultrasound. So, we're pretty worried about this picture on the right. Another screening test is the MRI. Now well MRI has gained a lot of new notoriety. At first none of us did MRI then everyone started doing MRIs. And now we've really come to a balance. Where we know that MRI is not needed for every patient in fact, it's not even needed for every cancer patient. In terms of screening, the only people who really need an MRI for screening are those at very high risk. And you'll remember that from our risk reduction lecture. Aside from that MRI is useful in very particular circumstances. It's helpful in cases of an undiagnosed primary. What do I mean by that? Sometimes, on your physical exam, for example, you may find a patient who presents with a lump in their armpit. In one of the axillary lymph nodes. And you may find that that actually is a cancer, but when you do a mammogram and an ultrasound you can't seem to find any cancer in the breast. MRI may be helpful in this circumstance because MRI is a very sensitive test and it can often find things that we don't see in other tests. But you have to be careful here. Because MRI also has a very high false positive rate. That is to say, it can often find things that are nothing at all. So be careful. But, an undiagnosed primary is one of the cases where it may be helpful. The second is in looking for suspected chest wall involvement. If you have a cancer that is sitting deep back in the breast and you're wondering about whether or not it's invaded through muscle. Well MRI can tell you that. MRI is often also a test that we use in patients who have implants. Because implant rupture has a very specific sign on an MRI, often called a linguini sign. And, MRI may be useful in following patients who get chemotherapy before surgery. We'll talk about this concept of neoadjuvant chemotherapy when we talk about the management of breast cancers but just keep it in mind that MRI may be useful in those circumstances. So how do we know when we have something that we should really be worried about versus something that we really shouldn't be worried about? Versus all the times in between. Well, our radiology colleagues help us out in this circumstance. At the end of any mammogram report, you'll find what's called a birads category. This is a lexicon that the radiologists use to convey how suspicious they are about their findings on the films. If they say it's a BIRAD zero it means they need more information. Maybe this was a screening mammogram and they need some more images or they're recommending an ultrasound or an MRI. If they say this is a BIRADS one that is to say everything looks completely negative. There is nothing to see, everything is normal. And the chances of any cancer being found is less than five and 10,000, similarly if they call it BIRADS two, a BIRADS two is a completely benign thing that they find in your imaging, again they're very confident that this is completely benign, chances in malignancy or less than five and 10,000. But maybe they see a cyst, like we saw on that ultrasound. We know this is a cyst. Nothing to worry about. For these categories, both the 1 and the 2, recommendation is just for regular routine follow up, usually once a year. What about a BIRADS Category 3? This is one that often throws many patients for a loop. The way that it's described is probably benign. And not surprisingly, the word probably gets patients a little bit anxious. But remember, even with a probably benign, the chances of this being malignant is less than 2%. People will use this if they see a solid but seemingly benign lump. That they just want to follow to make sure that it's not changing. Again, this is likely to be a fibroadenoma for example. And recommendations are to follow these every six months. Just until they can guarantee that they're stable and nothing to be worried about. The chances of this being a cancer are very low. Less than 2% and they don't need to be biopsied. But they do cause significant anxiety. What about a BIRADS 4? These are suspicious. It means that the radiologist is seeing something that they don't like and they need a biopsy to make sure that this isn't cancer. The chances of this being a cancer in general with a BIRADS four is 25 to 50% it means that they really don't like the look of it but they can't guarantee that its cancer. A BIRADS five Is starting to look pretty darn bad. Radiologists often have a lot of experience looking at mammograms and ultrasounds and MRIs, and when they call something a BIRADS 5, as one of my radiology colleagues once said. If it's not cancer, I'll eat my hat. In other words, their pretty darn sure that this is a cancer and highly suspicious. And so really want to get a biopsy to confirm that diagnosis. A BIRADS 6 is in patients who have already had a biopsy and we know that this is cancer. So that's a little bit about screening, and all of the techniques that we use to figure out what something might be, and how likely it is to be cancer. The next time we meet, we're going to talk about different biopsy techniques that'll really cinch the diagnosis. Until next time, I'm Dr. Anees Chagpar.
